What did the ""Turner Thesis"" explain? A. the end of agriculture industry in the U. S. B. the beginning of the Second Industrial Revolution C. the closing of the western frontier D. the opening of the final frontier

Option C, the closing of the western frontier, is the right answer.

Explanation:

An argument that claimed that American democracy was established by the American frontier came to be known as the Frontier Thesis. This argument was presented by historian Frederick Jackson Turner in the year 1893. He argued that the primary result of the American frontier was American democracy along with a lower interest in high culture, violence and egalitarianism.

the answer is states.

not really sure i needed the points. sorry